1. Technical Field
This invention relates to devices for processing contaminated blast media for reuse. Such contaminants are comprised of dust, paint, rust which are entrained within the spent blast medium after use.
2. Description of Prior Art
Prior art devices of this type have used a variety of separation methods and apparatus, see for example U.S. Pat. Nos. 4,394,256, 4,771,579, 5,035,089, 5,195,640, 5,185,968, 5,269,424 and 5,695,37.
In U.S. Pat. No. 4,394,256 a separation apparatus is illustrated having a re-circulation chamber in which spent abrasives are recirculated at high velocity using the chamber""s integral angled configuration to achieve primary separation.
U.S. Pat. No. 4,771,579 is directed to a cleaning and recovery device for abrasive blast media utilizing an internal air suspension in which media and contaminants of at least equal in weight drops out of the air suspension into a rotary filtered drum having a plurality of punch apertures within its surface to separate media and contaminants.
U.S. Pat. No. 5,035,089 claims a blast media recovery cleaning system having multiple separators. A fluidized bed is formed by use of a porous stone within a plenum. Compressed air is supplied to the stone so as to separate lower density materials from the higher density retaining the heavier materials within the plenum.
Applicant""s own U.S. Pat. No. 5,185,968 is directed to a mobile separation system for abrasive blasting material using a multi-step separation and cleaning process in which a magnetic drum separator is used to process the contaminated blast media along with an integral air wash system.
U.S. Pat. No. 5,195,640 defines an abrasive blast media cleaning device using a rotating drum separator that uses high velocity air stream there through into which the contaminated blast material is repeatedly scooped up and dropped within.
Applicant""s U.S. Pat. No. 5,269,424 claims a mobile apparatus for separation and recovery of spent abrasive blasting material utilizing magnetic drum separator in combination with an air wash dust collection and secondary wash for processing the blast media.
Finally, U.S. Pat. No. 3,695,385 discloses a recyclable abrasive blasting system and method utilizing multiple separation elements including a triple screening system.
A mobile apparatus for separation and recovery of abrasive blast material from entrained contaminants after use. A unique drum separator is used in combination with point intake and multiple outlet paths, one of which utilizes an air washer for final contaminant separation. The drum separator utilizes annular filtering slots of different sizes formed by independent spaced parallel annular angular inclined bands held together by radially spaced support rods. Abrasive blasts material is transported through the recovering drum separator by an integral continuous transportation vein affixed to its interior surface.